"I located a basic clue in the work of Helmut and Gerard, of the Neuro Chemical Institute," said Basil. "I refer, of course, to their studies of synaptical chemistry—in short, what happens when an impulse travels from nerve to nerve, which is the basic process of thought. Their findings are vastly interesting. When a stimulus is passed from one nerve to another, no less than twenty-one consecutive chemical reactions occur at the synapse. If any of these reactions is halted, the stimulus fails to pass the synapse."

Waylock said, "I think I see where you're leading."

"Here we have a suggestion on a means to control the thought processes of our catto. What we would like to do is to extirpate memory of his obstacle or problem. How to be selective? The obvious way is to attack one of the compounds, or its catalyst, at one or more synapses of the particular thought track. In order to be selective we choose a compound which is fugitive and which appears only during the process of thought transfer. I settled upon the substance Helmut and Gerard label heptant, because it has a highly definite chemical identity. The problem now is merely the formulation of a chelate which will weld to heptant, and remove it permanently from operative function. I farmed out the problem to Didactor Vauxine Tudderstell of the Maxart Bio-Chemical Clinic." Basil went to the cabinet, brought forth an orange bottle. "Here it is — anti-heptant. Water-soluble, non-toxic, highly effective. When it is present in the cerebral blood supply, it acts like the eraser button of a recorder, canceling whatever circuits are active, but inactive toward those not in use."